Temperature indicator



Sept. 16, 1941.

H. A. ANDREsEN v 2,256,007

TEMPERATURE INDICATOR I Filed uu'ly 24, 19:59

Patented Sept. 16, 1941 2,256,607 f'rEMrEaA'rUnE INDICATOR Hilmar A.Andresen, Chicago, lll., assignor to E.. iilniiann & Co., Chicago, Ill.,a corporation of Application July 24, 1939, Serial No. 286,263

6 Claims.

This invention relates to improvements in temperature indicators oftheitype that indicate the degrees of heat inside a chamber but arereadable from the outside thereof. I i

One of the objects of the present invention is to provide inatemperature indicator of the type mentioned, means to convert the slightmovement of a heat sensitive diaphragm responding tothe temperature of amedium, such as liquid within a chamber, into a greatly magnifiedrotating movement of an indicator outsidethe chamber.v

Another object is tov provide in a temperature indicator of theforegoing mentioned type, means whereby the casing of the vindicator'may be attached to a chamber such as'a tank orv the like so that onlythe inside face of a heat sensitive diaphragm carried by the casing willbe in contact with the contents oi' the chamber. L l

Yet another object of this invention is to provide, in a temperatureindicator of thetype described, means to readily attach the indicator toa tank or the like without danger-of breakage or displacement of theoperating parts of the indicator as a result of accidental contact of.the person ofithe installer or of tools with said parts.

A further object is to provide an air space tov serve as insulationbetween the diaphragm responsive to the temperature. of the mediumcontained in a tank or chamber and the indicator on the outside thereof.

A further object is to provide a .temperature indicator which is simplein construction and therefore inexpensive to manufacture and assemble.

Still a further object is to provide a temperature indicator includingan actuating diaphragm adapted to span an opening in a tank and therebyaccurately responsive to the temperature of a medium in the tank,sealing means being provided between the diaphragm and the tank toprevent leakage of the medium from the tank.

A further and more specific object is to provide sliding meansresponsive to the bowing of the diaphragm and cooperating with anindicator through motion converting and step up gearing mechanism. v

The above mentioned objects together with other objects and advantagesof this invention will become apparent as I proceed with thespecification.

In the accompanying drawing I have shown a preferred embodiment of myinvention. This drawing is not intended to be exhaustive and-is i not tobe taken as limiting of the invention, but on the contrary is chosenwith a view to illustrating my invention so that others skilledin theart may apply it under varying conditions of practical use and mayv makesuch modifications and changes therein as such conditions may-makedesirable. l

In the drawing:

my temperature indicator has been mounted;

Figure 2 is a plan view thereof Figure 3 is a sectional view on anenlarged scale taken on the line 3-3 of Figure 2;

Figure 4 is an enlarged view of the indicator shown` in Figure 1 .with arim removed and the major portion of a cover broken away, and

.of Figure 4 on a further enlarged scale.

Referringnow in detail tothe embodiment of the linvention illustrated inthe drawingflll indicates generally my temperature indicator attached toa chamber, tank or the like I I. 'Ihe tank I I is open to atmosphere asat I Ia and may be used yfor the storage of liquid or the like,v I

to and an` outlet pipe I Ic from the tank.

For convenience in-sillustration, the temperature indicator has beenshown as attached to the end of a chamber but obviously it would be'justas eiiicient if attached to the bottom thereof. Preferably, however, itis positioned just below the liquid level in the tank to obviate thenecessity ofV correction in the'temperature reading given `by theindicator for the head of liquid in the tank.

A cylindrical casing I 2, provided at one end with a fiange I3 andthreaded at its other end as v at Il serves as a housing for mytemperature indicator. A heat sensitive diaphragm I5 is secured' to theanged portion of the casing by means of a ring I 8 and countersunk fiathead screws I1. The diaphragm I5 is formed of bimetal or other suitableheat responsive material. The diaphragm I5, when it is subjected toheat. will become bowed as indicated by dotted lines in Figure 3.

I'he threaded portion I 4 internally recessed as indicated at I8 toprovide a seat I9 for a cup-like member 20. Centrally located on aybottom wall- 20a of the member 20 is an'apertured cylindrical extension2I provided with rspiral `cam surfaces 22. An actuating member or stubshaft 23 has slidablebearing in the yon the cam surfaces 22. The innerend of' the stub shaft 23 is in contact with the central portion of thediaphragm I5 and is slidably actuated Figure .1 is'an end elevation of atank on which Figure 5 is a vertical section on .the line 5-.5

show an inlet pipe I Ib for supplying liquid therevof the casing I2 isextension 2| and carries a cross pin 24 riding t 2 in one direction'bythe bowingmovement thereof.

` means of lugs one vdirection an amount The outer end of the shaft 23extends through z the wall 20a and has xed thereon a spur gear i' 25 inmesh with a pinion 26. l'Ihe pinion 26 has` a needle point bearing 21with the bottom wall 20a. lAn extension 21a of the pinion 26 isrotatively vjourrialed near its other end in a Z bracket g 26. One armof the bracket 23 is secured to the bottom wall 20a of the member 20 asby spot l welding indicated at 23a. 'I'he inner end of a` 'for theindicating disc, it

closely spaced and there would accordingly be more chance for variationfrom the tempera-ture 'in reading the indicator;

spiralhair spring 29 is secured in av slot 26a' in the cylindricalextension 21a of the pinion 26. The outer end vof the spring 29 issecured as by a wedge 3l to a pin 30 threaded or otherl, wise fixed onthe wall 20a.

. A dial l32 is secured to the extension 21a of.

the pinion 26 at a point outside the bearing ybracket 26. `A disk-like.cover 33 has an aperture 34 located therein to register with indicia 35of the dial 32. The cover 33 is fixed against rotation relative to thecuplike member as by 36 and openings 31. A rim 33 is threaded on thehousing 'I2 to retain the parts in proper operative relation to eachother. A comparatively large ,dead air space 39 is. provided between thediaphragm and the member 20 so that a minimum amount of heat will bepermitted to pass from the chamber. II to the moving parts of mytemperature indicator.

Practical operation The operation of my temperature indicator is -asfollows: As the temperature of the medium in the chamber or areceptacleII increases, it will cause the diaphragm I5 to expand or bow in degreeof heat within the chamber, thereby pushing the-stub shaft 23 outwardlythe samedistance. The pin 24 contact with the cam surfaces 22, therebyimparting to the shaft andspur gear25 a clockwise movement as viewed inFigure 4. The pinion 26 and :the dial 32 will be rotated an' increasednumber of degrees in a counterclockwise direction depending upon thetooth relation between the gear and pinion. Rotation of the pinionenergizes or winds up the spiral hair spring 29. As ja result of. theseoperations, one of the indicia indicatingl the degrees of heat .insidethe chamber will be brought to view through the opening 34.

As the temperature 'inside the chamber II decreases, the diaphragm I5 iscontracted thereby and the spring 29 will rotate the shaftl 23 in acounterclockwise direction through the pinion 26 and spur gear 25.

VThe pin 24 will with the cam surfaces 22 and the inner end of the shaft23 will be held in contact `with the retreating diaphragm I5. 'Ijheseoperations result in rotating the dial 32 in a reverse or clock-- afterassembly. iWith the room temperature known, it is merely necessary torotate the disc 32 to a position indicating that temperature whileholding the pinion 26 stationary. Thereafter the temperature indicationwill be in proper proportion to expansion of the diaphragm I5 and therewill always be an immediate response to be held thereby in contactvproportionate to the ilxed in the shaft 23 is in .While in describingthe invention I have re- -ferred In detail to the construction, form andarrangement of the various parts thereof, it isdiaphragm when subjectedto rising temperaturel of a medium in contact therewith, one end of saidhub having opposite helical faces and a cross pin carried by saidslidable member and coacting therewith to impart turning movement tosaid slidable member in proportion to the sliding movement thereof,anindicator operated in one direction by said slidable member, and meansfor biasing said indicator in the opposite direction, said last meanseffecting return ofsaid slidable member by` retention of said cross pinin contact with said opposite helical faces as said-diaphragm recedesbecause of the temperature of said medium decreasing.

2. In a device of the class described, a casing,

la heat sensitive diaphragm secured to one end of said casing,y anactuating member including a shaft actuated axially in one direction bysaid diaphragm when subjected to rising temperature, ahub rotatably andslidably receiving said shaft, a lateral projection on-said shaft, saidhub having a helical end adapted to be engaged by said projection toimpart turning movement to said actuating member proportionate to themovement of the diaphragm, an indicator dial driven in one direction bysaid actuating member, an index for registration with the graduations ofsaid dial, and spring means energized by the movement in saidonedirection of the indicator dial, said spring means effecting retentionof said projection in engagement with said helical end of said hub andreturn of said actuating member as said diaphragm recedes as a result oflowering temperature.

3. In a temperature indicator of the class de.

scribed, a casing having a hub provided with a helical face on one endthereof, a heat sensitive diaphragm secured to one end of said casingfor contact `with a liquid or the like; a stub shaft within `the casingand slidably actuated in one direction by said diaphragm, said shafthaving a projection Lcoacting with said helical face to constitute cammeans for imparting rotation to said stub shaft as said diaphragm slidesthe stub shaft in said direction, an indicator dial geared by step-upgearing to said stub shaft and thereby rotated a proportionately greaternumber of degrees by said stub shaft, said indicator dial being readablefrom outside said casing, and spring means energized by rotation of saidstub shaft in said one direction to retain said diaphragm, said stubshaft, said projection, said the scope of thel hub by said diaphragm,said'hub having a helical face and said stub shaft having a. lateralprojection cooperating therewith for imparting rotation to said stubshaft as a resulty of sliding movement thereof through said hub causedby said diaphragm. an indicator geared to, and ro-vl tated aproportionately greater number of degrees than said stub shaft, saidindicator being readable from outside said casing, and springmeansenergized by rotation oi' said stub shaft in one direction torotate the stub shaft in the opposite direction when the diaphragmrecedes invits movement.

5. In a temperature indicator. a casing,v means for mounting said casingon a tank or the like over an opening therein, a diaphragm carried bysaid casing, means for sealing the periphery of said diaphragm relativeto said tank surrounding said opening whereby the diaphragm spans theopening and is directly responsive to the temperature of the medium in.said tank, said diaphragm being formed of bimetallic material, aslidably and rotatably mounted shaft carried by said casing and engagingsaid diaphragm at substantially the center thereof, a cam `surfacestationary relative to said casing, a vprojection from said shaftcoactingtherewith for imparting rotation to said shaft as it is moved inone direction by said diaphragm, means biasing said shaft to revolve inan opposite direction to return it and keep said projection in contactwith said cam surface and said shaft in contact with said diaphragm, anindicator operatively connected with said shaft by means of step-upgearing, and a cover for said casing to enclose said indicator, biasingmeans and shaft, said cover having a window to observe the movement ofthe indicator.

6. A temperature indicator comprising a cylindrical casing, atemperaturev responsive disclike diaphragm on one end of said casing, acylindrical cuplike member in the other end of said casing, a stub shaftslidably and rotatively mounted in said cuplike member and actuated inone linear direction by said diaphragm abutting one end thereof, saidcuplike member having a helical surface,l said stub shaft having aprojection coacting therewith to cause rotation of said stub shaft as itis moved in a linear direction, an indicator element in said cuplikeelement having indicia to indicate the position thereof, means fortransmitting the rotational motion of said stub shaft to said indicatorelement, acover for said indicator element and cuplike member, saidcover having means to coact with an edge of said cuplike member toprevent rotation of one relative to the other and having a sight openingthrough which to view said indicator element,4 and spring meansenergized by rotation of said indicator element in one direction asimparted thereto by said stub shaft when actuated in said onelineardirection by said diaphragm, said spring means rotating said indicatorelement in the opposite direction and actuating said stub shaft in arotational direction to thereby retain said projection engaged with saidhelical surface and move the stub shaft in a linear direction oppositeto said one linear direction when said diaphragm recedes in itsmovement.

HILMAR A. ANDRESEN.

